Cargando…

Structure and Conformational Mobility of OLED-Relevant 1,3,5-Triazine Derivatives

A series of OLED-relevant compounds, consisting of 1,3,5-triazine core linked to various aromatic arms by amino group, has been synthesized and characterized. The studied compounds exist in solution as a mixture of two conformers, a symmetric propeller and asymmetric conformer, in which one of the a...

Descripción completa

Detalles Bibliográficos
Autores principales: Dobrikov, Georgi M., Nikolova, Yana, Slavchev, Ivaylo, Dangalov, Miroslav, Deneva, Vera, Antonov, Liudmil, Vassilev, Nikolay G.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: MDPI 2023
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9921695/
https://www.ncbi.nlm.nih.gov/pubmed/36770913
http://dx.doi.org/10.3390/molecules28031248
_version_ 1784887373526466560
author Dobrikov, Georgi M.
Nikolova, Yana
Slavchev, Ivaylo
Dangalov, Miroslav
Deneva, Vera
Antonov, Liudmil
Vassilev, Nikolay G.
author_facet Dobrikov, Georgi M.
Nikolova, Yana
Slavchev, Ivaylo
Dangalov, Miroslav
Deneva, Vera
Antonov, Liudmil
Vassilev, Nikolay G.
author_sort Dobrikov, Georgi M.
collection PubMed
description A series of OLED-relevant compounds, consisting of 1,3,5-triazine core linked to various aromatic arms by amino group, has been synthesized and characterized. The studied compounds exist in solution as a mixture of two conformers, a symmetric propeller and asymmetric conformer, in which one of the aromatic arms is rotated around the C-N bond. At temperatures below −40 °C, the VT NMR spectra in DMF-d7 are in a slow exchange regime, and the signals of two conformers can be elucidated. At temperatures above 100 °C, the VT NMR spectra in DMSO-d6 are in a fast exchange regime, and the averaged spectra can be measured. The ratio of symmetric and asymmetric conformers in DMF-d7 varies from 14:86 to 50:50 depending on the substituents. The rotational barriers of symmetric and asymmetric conformers in DMF-d7 were measured for all compounds and are in the interval from 11.7 to 14.7 kcal/mol. The ground-state energy landscapes of the studied compounds, obtained by DFT calculations, show good agreement with the experimental rotational barriers. The DFT calculations reveal that the observed chemical exchange occurs by the rotation around the C(1,3,5-triazine)-N bond. Although some of the compounds are potentially tautomeric, the measured absorption and emission spectra do not indicate proton transfer neither in the ground nor in the excited state.
format Online
Article
Text
id pubmed-9921695
institution National Center for Biotechnology Information
language English
publishDate 2023
publisher MDPI
record_format MEDLINE/PubMed
spelling pubmed-99216952023-02-12 Structure and Conformational Mobility of OLED-Relevant 1,3,5-Triazine Derivatives Dobrikov, Georgi M. Nikolova, Yana Slavchev, Ivaylo Dangalov, Miroslav Deneva, Vera Antonov, Liudmil Vassilev, Nikolay G. Molecules Article A series of OLED-relevant compounds, consisting of 1,3,5-triazine core linked to various aromatic arms by amino group, has been synthesized and characterized. The studied compounds exist in solution as a mixture of two conformers, a symmetric propeller and asymmetric conformer, in which one of the aromatic arms is rotated around the C-N bond. At temperatures below −40 °C, the VT NMR spectra in DMF-d7 are in a slow exchange regime, and the signals of two conformers can be elucidated. At temperatures above 100 °C, the VT NMR spectra in DMSO-d6 are in a fast exchange regime, and the averaged spectra can be measured. The ratio of symmetric and asymmetric conformers in DMF-d7 varies from 14:86 to 50:50 depending on the substituents. The rotational barriers of symmetric and asymmetric conformers in DMF-d7 were measured for all compounds and are in the interval from 11.7 to 14.7 kcal/mol. The ground-state energy landscapes of the studied compounds, obtained by DFT calculations, show good agreement with the experimental rotational barriers. The DFT calculations reveal that the observed chemical exchange occurs by the rotation around the C(1,3,5-triazine)-N bond. Although some of the compounds are potentially tautomeric, the measured absorption and emission spectra do not indicate proton transfer neither in the ground nor in the excited state. MDPI 2023-01-27 /pmc/articles/PMC9921695/ /pubmed/36770913 http://dx.doi.org/10.3390/molecules28031248 Text en © 2023 by the authors. https://creativecommons.org/licenses/by/4.0/Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).
spellingShingle Article
Dobrikov, Georgi M.
Nikolova, Yana
Slavchev, Ivaylo
Dangalov, Miroslav
Deneva, Vera
Antonov, Liudmil
Vassilev, Nikolay G.
Structure and Conformational Mobility of OLED-Relevant 1,3,5-Triazine Derivatives
title Structure and Conformational Mobility of OLED-Relevant 1,3,5-Triazine Derivatives
title_full Structure and Conformational Mobility of OLED-Relevant 1,3,5-Triazine Derivatives
title_fullStr Structure and Conformational Mobility of OLED-Relevant 1,3,5-Triazine Derivatives
title_full_unstemmed Structure and Conformational Mobility of OLED-Relevant 1,3,5-Triazine Derivatives
title_short Structure and Conformational Mobility of OLED-Relevant 1,3,5-Triazine Derivatives
title_sort structure and conformational mobility of oled-relevant 1,3,5-triazine derivatives
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9921695/
https://www.ncbi.nlm.nih.gov/pubmed/36770913
http://dx.doi.org/10.3390/molecules28031248
work_keys_str_mv AT dobrikovgeorgim structureandconformationalmobilityofoledrelevant135triazinederivatives
AT nikolovayana structureandconformationalmobilityofoledrelevant135triazinederivatives
AT slavchevivaylo structureandconformationalmobilityofoledrelevant135triazinederivatives
AT dangalovmiroslav structureandconformationalmobilityofoledrelevant135triazinederivatives
AT denevavera structureandconformationalmobilityofoledrelevant135triazinederivatives
AT antonovliudmil structureandconformationalmobilityofoledrelevant135triazinederivatives
AT vassilevnikolayg structureandconformationalmobilityofoledrelevant135triazinederivatives